[fargogirl51]

Hello all. I am working on a retrosynthesis project for my class and I am really struggling. I have a few ideas of where to go after I break the product molecule down but I am not sure how to start the retrosynthesis. If anyone could give me some idea or a jump start, that would be much appreciated. I have attached a picture of my ideas for steps further down the line but I am not really confident in those either. Would the Hantzsch Synthesis or something similar work? The only stipulation is that we can only use 3-Carbon building blocks.

[kriggy]

Its not very visible, could you post better photo or use a drawing software?

[fargogirl51]

I tried taking another picture to see if this is more clear. I'm not very familiar with using the drawing software. Hopefully my attempts are a little clearer here.

[fargogirl51]

I'm trying out a chemical drawing program to give some better formatting of the product molecule so at least that part is a little easier to see. Hoping I am using it correctly. Sorry about the watermark; I am using a free trial of the program for now.

I've been working more on the synthesis and am trying to synthesize the tetrahydrothiophene portion using 4-bromobutane-1-thiol and OH via an SN2 reaction but I am not sure how to break 4-bromobutane-1-thiol down further. Again, my main issue is breaking down the main molecule into the pyridine and tetrahydrothiophene portions. I am also unsure how to further break down pyridine as an unsubstituted molecule. All of the mechanisms I know to synthesize pyridine would leave it as an unsubstituted molecule. I'm afraid this project is proving beyond my skill set.

[orgopete]

I'm inferring from this problem that it is being taken from a class on heterocycles or a section concentrating on heterocycles. Therefore the idea of simply building a tetrahydrothiophene without a thought as to how it would become connected to the pyridine seems to be missing an important step. It looks to me as though the connections are portions of the pyridine synthesis. A pyridine seems likely to have involved some kind of carbonyl chemistry, especially everything must be built from three carbons or less. This suggests building blocks from acetaldehyde, acetate, acetone, or acetylene (or something like that, you should get the idea).

[fargogirl51]

Ok, after much hair-pulling, this is what I came up with. I split it into 3 pictures for different parts of the retrosynthesis. If anyone has a chance, I'd love if someone could just point out anything that doesn't work. I am not sure about my sterics, etc. at all.